Slowly Moving to Metric

Topics related to wrapped rotary machining in Aspire or VCarve Pro
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TReischl
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Slowly Moving to Metric

Post by TReischl »

No, no, no, I am not an old "anti metric" curmudgeon by any means. However. . . . .

I have been using Porter Cable routers for years and years. They come with 1/4 and 1/2 inch collets. Over the years I added 1/8 and 3/8 collets. Sooo, with imperial collets one buys imperial tools. Simple as that.

Enter the chinese. I have been able to buy some 1/8 ball nose and regular bits. But bigger than that? Iffy. I have had really good luck with the chinese HSS bits. I cut mostly softwood and domestic hardwoods. Virtually no MDF, Plywood or abrasive exotics. So HSS works better than carbide for me, especially at the ridiculously low chinese prices. In my oh so humble opinion HSS produces a better cut in softwoods with less fuzzies.

Today I was looking at the great prices for 6mm bits on the big auction site. Thinking to myself, I wonder. . . . does anyone sell a 6mm collet for the PC routers? Indeed, they do! And 8mm, 10mm, 12mm too.

The point of this post is that if you are using a router for your spindle and you would like to be able to use some of the inexpensive chinese tooling available, shop around for a collet set. I had no idea that folks were making metric collets for the PC and a lot of other routers. It is NOT a good idea to use a .25 collet to try to hold a 6mm tool. It is not going to run even close to true not to mention springing the collet so that it never runs true with a 1/4 shank again. That "1/8" stuff I have been using is probably 3mm, but springing the collet about .005-.006 is not that big of a deal evidently. I highly doubt our chinese friends actually grind those cutter shanks to .125.
"If you see a good fight, get in it." Dr. Vernon Johns

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ChrisInEstes
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Re: Slowly Moving to Metric

Post by ChrisInEstes »

Me too! So far I've switched from quarts of beer to liters. I get an extra 1.814 ounces of beer, but it looks the same as a quart.

Chris
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garylmast
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Re: Slowly Moving to Metric

Post by garylmast »

I grew up using imperial measurements, but when I got my CNC machine, the settings were in metric. I found the more I used metric, the more I preferred it. I have a combination imperial/metric ruler where it's 1mm segments vs. 1/16-in, so when using it I get a more actuate measurement using metric. Just remember 25.4 mm = 1-inch.

Also, most 3-D models you download is going to be in metric, so whether I model them myself or download, I've got in the habit of setting my software in metric. In Aspire, it doesn't matter if you're modeling it in imperial or metric measurements, when you save the toolpath, it will make the conversion, so I really use both.

As far as Chinese mills, I usually go hog-wild and get a quote for several dozen when I purchase them, because in a quantity of a few hundred dollars you can get 5 or 6 of them for the price of one from the U.S. I've used both and so far I can't tell the difference in one being better than the other. I was really upset when I broke a $150 U.S. made mill where the same one I got from China was $35. Besides eBay, a good source is Alibaba.com .


I posted this PDF file of Fraction/Decimal/Metric once before, but I'll do it again here. I have a copy on my computer and also laminated and posted on my shop wall, where I constantly refer to it.

Gary
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highpockets
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Re: Slowly Moving to Metric

Post by highpockets »

I keep a set of imperial/metric digital calipers around. Just open to the desired measurement and press the button. This way I also get a visual reference to the measurement.
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Leo
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Re: Slowly Moving to Metric

Post by Leo »

My calipers have a button to switch from in to mm just by pressing the button.

I grew up in the USA where we (gov.gov) refuses to switch, so I use Imperial most of the time. BUT as an engineer I see mm about half the time. In college we used mm more than imperial.

Working so many years in the machining world in & mm are common. ER collets cover "ranges", for instance ER16 5-6mm. This is up for a lot of debate as to the good and bad. I like exact fit but it is not critical, especially in wood.

Sooo - to me, my default is inches, but there is really no difference - it's just a number.

My machine is 1300 x 1300 x 254 - but I still think of it as 51 x 51 x 10
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Re: Slowly Moving to Metric

Post by ger21 »

ER collets cover "ranges", for instance ER16 5-6mm.
They also come in imperial sizes.
If you use 6mm bits, buy a 6mm collet. If you use 1/4" bits, get a 1/4" collet.
Gerry - http://www.thecncwoodworker.com

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Re: Slowly Moving to Metric

Post by dhellew2 »

I agree with ger21.

The design of the ER collet allows for the use of imperial and metric in the same collet with no impact on run out.
I've had mine for a long time and rarely use the router without the holder in the chuck.

The collet inserts have a size range.
I have extra nuts so I can quickly switch to the next size needed for the same part.
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TReischl
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Re: Slowly Moving to Metric

Post by TReischl »

I do not have one of those fancy electronic calipers with a button. Well, I do, but it is a really cheap one from HF. I am not crazy about the electronic ones. I have an old Mitutoyo with the dial face. I dunno, I just like those dials for some weird reason.

I have been hoping that my router dies one of these days. Would love to convert over to a real spindle with ER collets. I use ER collets on my mini mill and on the lathe (not a mini lathe). IIRC I have a set of ER 32's for the lathe and ER 20 for the mill. I am just too cheap to retire that router. It is about 5 years old now. The speed control is stuck on about 14K rpm. Which, I sort of like. Much, much quieter and surprisingly I have not had to adjust feed rates to any significant degree. Normal feed rates for me are anywhere from 50IPM to 250IPM. Mostly I run at about 150 these days.
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Slowly Moving to Metric

Post by Bobtail Farm »

I added a 1/2" shank ER20 adapter (< $13 all-in) to my 1/2" router ... adding runout for sure, but gained access to inexpensive collets ($0.99 all-in, imperial and metric) in a variety of sizes. And I too have visions that one day, when my router gives up, I will rebuild with a spindle. But in the meanwhile... the ER adapter works good enough for me. Yes, I recognize you get what you pay for, but cost is a relevant constraint to my hobby. :-)

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